Prosthesis connection mechanism

The present invention is directed to systems or mechanisms for affixing a prosthesis or portion of a prosthesis to bone.

The present disclosure relates to mechanisms for affixing prostheses to bone, and more particularly, systems for affixing at least a portion of a prosthesis to bone.

A prosthesis comprising a component for engaging a surface of a vertebral body is disclosed. The component comprises a bone-engaging surface and an outer surface that is not bone-engaging, wherein the bone-engaging surface is configured to engage a portion of the surface of the vertebral body, wherein the vertebral body has been configured to engage with the bone-engaging surface, and wherein after the component is engaged with the vertebral body, at least at a location of an area of a junction between a vertical surface and an endplate surface of the vertebral body, the outer surface of the component has a shape that is substantially similar to an anatomical shape of the vertebral body.

Additional aspects and features of the present disclosure will be apparent from the detailed description and claims as set forth below.

FIG. 1 shows a schematic, cross-sectional view of two adjacent vertebral bodies after a disc situated between the two has been removed;

FIG. 2 is a schematic, cross-sectional view of a prosthesis in a sagittal plane;

FIG. 2A is a frontal view of the prosthesis of FIG. 2 , i.e., a view from the anterior side of vertebral bodies V 1 and V 2 ;

FIG. 2B is a frontal view of an alternate prosthesis of FIG. 2 ;

FIG. 3 is a schematic, cross-sectional view of another prosthesis in a sagittal plane;

FIG. 3A is a frontal view of the prosthesis of FIG. 3 , i.e., a view from the anterior side of vertebral bodies;

FIG. 3B is a frontal view of alternate prosthesis of FIG. 3 ;

FIG. 4 is a schematic, cross-sectional view of another prosthesis in a sagittal plane; and

FIG. 5 is a schematic, cross-sectional view of another prosthesis in a sagittal plane.

For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments, or examples, illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alterations and further modifications in the described embodiments, and any further applications of the principles of the invention as described herein are contemplated as would normally occur to one skilled in the art to which the invention relates.

FIG. 1 shows a schematic, cross-sectional view of two adjacent vertebral bodies V 1 and V 2 after a disc situated between the two is removed. FIG. 1 depicts a superior vertebral body V 1 , an inferior vertebral body V 2 , and a disc space 50 between the two vertebral bodies V 1 and V 2 . Reference marker A represents an anterior side of the vertebral bodies V 1 and V 2 , whereas reference marker P represents a posterior side of the vertebral bodies V 1 and V 2 . As shown in FIG. 1 , superior vertebral body V 1 has an anterior vertical surface 12 , a posterior vertical surface 14 , an endplate surface 10 , and a junction 11 between the vertical surface 12 and the endplate surface 10 . Similarly, as shown in FIG. 1 , inferior vertebral body V 2 has an anterior vertical surface 12 A, a posterior vertical surface 14 A, an endplate surface 10 A, and a junction 11 A between the vertical surface 12 A and the endplate surface 10 A. FIG. 1 shows a schematic, cross-sectional view of an anatomical shape of the vertebral body V 1 .

FIG. 2 shows a schematic, cross-sectional view of a prosthesis 100 in a sagittal plane, situated primarily in the disc space 50 between vertebral bodies V 1 and V 2 . Reference marker A represents an anterior side of the vertebral bodies V 1 and V 2 , whereas reference marker P represents a posterior side of the vertebral bodies V 1 and V 2 . The prosthesis 100 comprises a component 20 for engaging a surface of a vertebral body V 1 . The component 20 comprises a bone-engaging surface 21 and an outer surface 26 that is not bone-engaging, wherein the bone-engaging surface 21 is configured to engage a portion of the surface of the vertebral body V 1 , wherein the vertebral body V 1 has been configured to engage with the bone-engaging surface 21 . After the component 20 is engaged with the vertebral body V 1 , at least at a location of an area 24 of the junction 11 between the vertical surface 12 and the endplate surface 10 of the vertebral body V 1 , an outer surface 24 S at area 24 of the component 20 has a shape that is substantially similar to an anatomical shape of the vertebral body V 1 . An anatomical shape of junction 11 is shown in FIG. 1 . Note that component 20 comprises portion 22 that is situated at the location of junction 11 , and the area where portion 22 engages the vertebral body V 1 is labeled by reference marker 24 .

The term “substantially” (or “substantial”) as used herein may be applied to modify any quantitative representation which could permissibly vary without resulting in a change in the basic function to which it is related. For example, while the outer surface 24 AS of the component 20 is not necessarily identical to an anatomical shape of junction 11 of vertebral body V 1 , it is substantially similar. Specifically, system 100 is designed so that component 20 or other parts of the prosthesis 100 at least at a location of area 24 of junction 11 do not interfere, or if any, provide minimal interference with existing tissue at the location of junction 11 .

As shown in FIG. 2 , at the junction 11 between the vertical surface 12 and the endplate surface 10 of the vertebral body V 1 , the bone-engaging surface 21 of the component 20 has a cross-sectional shape in a sagittal plane that comprises a convex shape 22 X, and the vertebral body V 1 has a concave shape 11 X at the same area 24 to engage with the surface 22 X. Note that the outer surface of component 20 at portion 22 is labeled by reference marker 22 Y. As shown in FIG. 2 , outer surface 22 Y has a concave shape.

Also, as shown in FIG. 2 , the prosthesis 100 further comprises a component 20 A for engaging a surface of a vertebral body V 2 . The component 20 A comprises a bone-engaging surface 21 A and an outer surface 26 A that is not bone-engaging, wherein the bone-engaging surface 21 A is configured to engage a portion of the surface of the vertebral body V 2 , wherein the vertebral body V 2 has been configured to engage with the bone-engaging surface 21 A. After the component 20 A is engaged with the vertebral body V 2 , at least at a location of an area 24 A of junction 11 A between the vertical surface 12 A and the endplate surface 10 A of the vertebral body V 2 , an outer surface 24 AS at area 24 A of the component 20 A has a shape that is substantially similar to an anatomical shape of the vertebral body V 2 . An anatomical shape of junction 11 A is shown in FIG. 1 . Note that component 20 A comprises portion 22 A that is situated at the location of junction 11 A, and the area where portion 22 A engages the vertebral body V 2 is labeled by reference marker 24 A.

Also, similar to component 20 , as shown in FIG. 2 , component 20 A and vertebral body V 2 have similar configurations at the junction 11 A between the vertical surface 12 A and the endplate surface 10 A of the vertebral body V 2 . That is, the bone-engaging surface 21 A of the component 20 A has a cross-sectional shape in a sagittal plane that comprises a convex shape 21 AX, and the vertebral body V 1 has a concave shape 11 AX at the same area 24 A to engage with surface 21 AX. Note that the outer surface of component 20 at portion 22 is labeled by reference marker 22 AY. Also, as shown in FIG. 2 , outer surface 22 AY has a concave shape.

Also, as shown in FIG. 2 , a fastener 40 is used to affix part 22 of component 20 to the area 24 of junction 11 of vertebral body V 1 . Fastener 40 has a distal end 44 and a fastener head 42 . As shown in FIG. 2 , after the component 20 is engaged with the vertebral body V 1 and fastener 40 is inserted in its intended final position, at the area 24 of junction 11 between the vertical surface 12 and the endplate surface 10 of the vertebral body V 1 where the head 42 of fastener 40 is located, an outer surface 24 S at area 24 of the head 42 of the fastener 40 in combination with the outer surface of component 20 has a shape that is substantially similar to an anatomical shape of the vertebral body V 1 . FIG. 2 shows fastener 40 in its intended final position, where as shown, the head 42 contacts the outer surface 22 Y of component 20 .

Similarly, as shown in FIG. 2 , a fastener 40 A is used to affix part 22 A of component 20 A to the area 24 A of junction 11 A of vertebral body V 2 . Fastener 40 A has a distal end 44 A and a fastener head 42 A. As shown in FIG. 2 , after the component 20 A is engaged with the vertebral body V 2 and fastener 40 A is inserted in its intended final position, at the area 24 A of junction 11 A between the vertical surface 12 A and the endplate surface 10 A of the vertebral body V 2 where the head 42 A of fastener 40 A is located, an outer surface 24 AS at area 24 A of the head 42 A of the fastener 40 A in combination with the outer surface of component 20 A has a shape that is substantially similar to an anatomical shape of the vertebral body V 2 . FIG. 2 shows fastener 40 A in its intended final position, where as shown, the head 42 A contacts the outer surface 22 AY of component 20 A. Fastener 40 and/or fastener 40 A may be any device to help affix their respective components to the respective vertebral bodies, for example, a screw.

Also, as shown in FIG. 2 , component 20 may further comprise structures 28 to help affix component 20 to vertebral body V 1 . Structures 28 may be anchors, keels, spikes, pegs, prongs, or similar structures to help component 20 affix to vertebral body V 1 . Similarly, component 20 A may further comprise structures 28 A to help affix component 20 A to vertebral body V 2 . Structures 28 A may be anchors, keels, spikes, pegs, prongs, or similar structures to help component 20 A affix to vertebral body V 2 . Surface coatings such as Hydroxyapatite (HA), plasma spray or beading also may be used instead of or in addition to respective structures 28 and 28 A to help affix components to their respective vertebral bodies.

FIG. 2A shows a frontal view of prosthesis 100 of FIG. 2 . This view is from the anterior side of vertebral bodies V 1 and V 2 , where reference marker L represents lateral sides of vertebral bodies V 1 and V 2 . As shown in FIG. 2A , component 20 comprises a single portion 22 that is situated at the location of junction 11 , and the area where portion 22 engages the vertebral body V 1 is labeled by reference marker 24 . Portion 22 provides an area 24 for helping component 20 affix to vertebral body V 1 . Further, as shown, portion 22 comprises a fastener-receiving hole 30 configured to receive fastener 40 and for allowing fastener 40 to engage the vertebral body V 1 . As shown in FIG. 2 , the fastener-receiving hole 30 is configured to allow the fastener 40 to engage the vertebral body V 1 in a direction toward the substantial center of the vertebral body V 1 . As shown in the frontal view of FIG. 2A , fastener head 42 is visible.

Similarly, as shown in FIG. 2A , component 20 A comprises a single portion 22 A that is situated at the location of junction 11 A, and the area where portion 22 A engages the vertebral body V 2 is labeled by reference marker 24 A. Portion 22 A provides an area 24 A for helping component 20 A affix to vertebral body V 2 . Further, as shown, portion 22 A comprises a fastener-receiving hole 30 A configured to receive fastener 40 A and for allowing fastener 40 A to engage the vertebral body V 2 . As shown in FIG. 2 , the fastener-receiving hole 30 A is configured to allow the fastener 40 A to engage the vertebral body V 2 in a direction toward the substantial center of the vertebral body V 2 . As shown in the frontal view of FIG. 2A , fastener head 42 A is visible.

FIG. 2B shows a frontal view of an alternate prosthesis 100 of FIG. 2 . This view is from the anterior side of vertebral bodies V 1 B and V 2 B, where reference marker L represents lateral sides of vertebral bodies V 1 B and V 2 B. As shown in FIG. 2B , component 20 B comprises three portions 22 B, each of which are situated at different areas 24 B along junction 11 , and the areas where portions 22 B engage the vertebral body V 1 B are labeled by reference markers 24 B. Each Portion 22 B provides an area 24 B for helping component 20 B affix to vertebral body V 1 B. Further, as shown, each portion 22 B comprises a fastener-receiving hole 30 B for receiving a fastener. As shown in the frontal view of FIG. 2B , fastener heads 42 B are visible. Similarly, as shown in FIG. 2B , the component affixed to vertebral body V 2 B comprises three portions for helping affix it to vertebral body V 2 B.

FIG. 3 shows a schematic, cross-sectional view of a prosthesis 200 in a sagittal plane, situated primarily in the disc space 50 between vertebral bodies, labeled V 3 and V 4 in FIG. 3 . Reference marker A represents an anterior side of the vertebral bodies V 3 and V 4 , whereas reference marker P represents a posterior side of the vertebral bodies V 3 and V 4 . The prosthesis 200 comprises a component 120 for engaging a surface of a vertebral body V 3 . The component 120 comprises a bone-engaging surface 110 and an outer surface 126 that is not bone-engaging, wherein the bone-engaging surface 110 is configured to engage a portion of the surface of the vertebral body V 3 , wherein the vertebral body V 3 has been configured to engage with the bone-engaging surface 110 . After the component 120 is engaged with the vertebral body V 3 , at least at a location of the area 124 of junction 11 between the vertical surface 112 and the endplate surface 110 of the vertebral body V 3 (junction 11 not shown in FIG. 3 , but is represented as junction 11 in FIG. 1 ), an outer surface 124 S at area 124 of the component 120 has a shape that is substantially similar to an anatomical shape of the vertebral body V 3 . An anatomical shape of junction 11 is shown in FIG. 1 . Note that component 120 comprises portion 122 that is situated at the location of junction 11 , and the area where portion 122 engages the vertebral body V 3 is labeled by reference marker 124 .

Also, as shown in FIG. 3 , the prosthesis 200 further comprises a component 120 A for engaging a surface of a vertebral body V 4 . The component 120 A comprises a bone-engaging surface 110 A and an outer surface 126 A that is not bone-engaging, wherein the bone-engaging surface 110 A is configured to engage a portion of the surface of the vertebral body V 4 , wherein the vertebral body V 4 has been configured to engage with the bone-engaging surface 110 A. After the component 120 A is engaged with the vertebral body V 4 , at least at a location of the area 124 A of junction 11 A between the vertical surface 112 A and the endplate surface 110 A of the vertebral body V 4 (junction 11 A not shown in FIG. 3 , but is represented as junction 11 A in FIG. 1 ), an outer surface 124 AS at area 124 A of the component 120 A has a shape that is substantially similar to an anatomical shape of the vertebral body V 4 . An anatomical shape of junction 11 A is shown in FIG. 1 . Note that component 120 A comprises portion 122 A that is situated at the location of junction 11 A, and the area where portion 122 A engages the vertebral body V 4 is labeled by reference marker 124 A.

As shown in FIG. 3 , area 124 of component 120 has a bone-engaging surface 122 X that has a cross-sectional shape in a sagittal plane that comprises a convex shape 122 X, and the vertebral body V 3 has a concave shape 111 X at the same area 124 to engage with surface 122 X. As shown in FIG. 3 , component 120 A has a similar configuration at area 124 A. One difference between prosthesis 200 and prosthesis 100 is that a fastener 40 or 40 A are not used with prosthesis 200 . Thus, there is no fastener located at areas 124 or 124 A.

As shown in FIG. 3 , component 120 may further comprise structures 128 to help affix component 120 to vertebral body V 3 . Structures 128 may be anchors, keels, spikes, pegs, prongs, or similar structures to help component 120 affix to vertebral body V 3 . Similarly, component 120 A may further comprise structures 128 A to help affix component 120 A to vertebral body V 4 . Structures 128 A may be anchors, keels, spikes, pegs, prongs, or similar structures to help component 120 A affix to vertebral body V 4 . Surface coatings such as Hydroxyapatite (HA), plasma spray or beading also may be used instead of or in addition to respective structures 128 and 128 A to help affix components to their respective vertebral bodies.

FIG. 3A shows a frontal view of prosthesis 200 of FIG. 3 . This view is from the anterior side of vertebral bodies V 3 and V 4 , where reference marker L represents lateral sides of vertebral bodies V 3 and V 4 . As shown in FIG. 3A , component 120 comprises a single portion 122 that is situated at the location of junction 11 , and the area where portion 122 engages the vertebral body V 3 is labeled by reference marker 124 . Portion 122 does provide an area 124 for helping component 120 affix to vertebral body V 3 , but portion 122 does not have a fastener-receiving hole for receiving a fastener. Similarly, as shown in FIG. 3A , component 120 A has a similar configuration of portion 122 A at location 124 A.

FIG. 3B shows a frontal view of an alternate prosthesis 200 of FIG. 3 . This view is from the anterior side of vertebral bodies V 3 B and V 4 B, where reference marker L represents lateral sides of vertebral bodies V 3 B and V 4 B. As shown in FIG. 3B , component 120 B comprises three portions 122 B, each of which are situated at different areas 124 B along junction 11 , and the areas where portions 122 B engage the vertebral body V 1 B are labeled by reference markers 124 B. Each Portion 122 B provides an area 124 B for helping component 120 B affix to vertebral body V 3 B, although portions 122 B do not have fastener-receiving holes. Similarly, as shown in FIG. 3B , the component affixed to vertebral body V 4 B comprises three portions for helping affix it to vertebral body V 4 B.

FIG. 4 shows a schematic, cross-sectional view of a prosthesis 300 in a sagittal plane, situated primarily in the disc space 50 between vertebral bodies V 5 and V 6 . Reference marker A represents an anterior side of the vertebral bodies V 5 and V 6 , whereas reference marker P represents a posterior side of the vertebral bodies V 5 and V 6 . The prosthesis 300 comprises a component 220 for engaging a surface of a vertebral body V 5 . The component 220 comprises a bone-engaging surface 210 and an outer surface 226 that is not bone-engaging, wherein the bone-engaging surface 210 is configured to engage a portion of the surface of the vertebral body V 5 , wherein the vertebral body V 5 has been configured to engage with the bone-engaging surface 210 . After the component 120 is engaged with the vertebral body V 5 , at least at a location of the area 224 of junction 11 between the vertical surface 212 and the endplate surface 210 of the vertebral body V 1 (junction 11 not shown in FIG. 4 , but is represented as junction 11 in FIG. 1 ), an outer surface 224 S at area 224 of the component 220 has a shape that is substantially similar to an anatomical shape of the vertebral body V 5 . An anatomical shape of junction 11 is shown in FIG. 1 . Note that component 220 comprises portion 222 that is situated at the location of junction 11 , and the area where portion 222 engages the vertebral body V 5 is labeled by reference marker 224 .

As shown in FIG. 4 , at the area 224 of junction 11 between the vertical surface 212 and the endplate surface 210 of the vertebral body V 5 , the bone-engaging surface 210 of the component 220 has a cross-sectional shape in a sagittal plane that comprises a portion of substantially zero curvature 211 X, and the vertebral body V 1 has a portion of substantially zero curvature 222 X at the same area 224 to engage with surface 211 X.

Also, as shown in FIG. 4 , the prosthesis 300 further comprises a component 220 A for engaging a surface of a vertebral body V 6 . The component 220 A comprises a bone-engaging surface 210 A and an outer surface 226 A that is not bone-engaging, wherein the bone-engaging surface 210 A is configured to engage a portion of the surface of the vertebral body V 6 , wherein the vertebral body V 6 has been configured to engage with the bone-engaging surface 210 A. After the component 220 A is engaged with the vertebral body V 6 , at least at a location of the area 224 A of junction 11 A between the vertical surface 212 A and the endplate surface 210 A of the vertebral body V 6 (junction 11 A not shown in FIG. 4 , but is represented as junction 11 A in FIG. 1 ), an outer surface 224 AS at area 224 A of the component 220 A has a shape that is substantially similar to an anatomical shape of the vertebral body V 6 . An anatomical shape of junction 11 A is shown in FIG. 1 . Note that component 220 A comprises portion 222 A that is situated at the location of junction 11 A, and the area where portion 222 A engages the vertebral body V 6 is labeled by reference marker 224 A.

Also, similar to component 220 , as shown in FIG. 4 , component 220 A and vertebral body V 6 have similar configurations at the area 224 A of junction 11 A between the vertical surface 212 A and the endplate surface 210 A of the vertebral body V 6 . That is, the bone-engaging surface 212 A of the component 220 A has a cross-sectional shape in a sagittal plane that comprises a portion of substantially zero curvature 211 AX, and the vertebral body V 6 has a portion 222 AX of substantially zero curvature at the same area 224 A to engage with the surface 211 AX of component 220 A. Note that the outer surface of component 220 A at portion 222 A is labeled by reference marker 224 AS.

As shown in FIG. 4 , component 220 may further comprise structures 228 to help affix component 220 to vertebral body V 5 . Structures 228 may be anchors, keels, spikes, pegs, prongs, or similar structures to help component 220 affix to vertebral body V 5 . Similarly, component 220 A may further comprise structures 228 A to help affix component 220 A to vertebral body V 6 . Structures 228 A may be anchors, keels, spikes, pegs, prongs, or similar structures to help component 220 A affix to vertebral body V 6 . Surface coatings such as Hydroxyapatite (HA), plasma spray or beading also may be used instead of or in addition to respective structures 228 and 228 A to help affix components to their respective vertebral bodies.

As with prosthesis 200 of FIG. 3 , portion 222 of prosthesis 300 of FIG. 4 does provide an area 224 for helping component 220 affix to vertebral body V 5 , but portion 222 does not have a fastener-receiving hole for receiving a fastener. Similarly, as shown in FIG. 4 , component 220 A has a similar configuration of portion 222 A at location 224 A.

FIG. 5 shows a schematic, cross-sectional view of a prosthesis 400 in a sagittal plane, situated primarily in the disc space 50 between vertebral bodies V 5 and V 6 . Reference marker A represents an anterior side of the vertebral bodies V 7 and V 8 , whereas reference marker P represents a posterior side of the vertebral bodies V 7 and V 8 . The prosthesis 400 is an interbody fusion device comprising two bone-engaging surface 310 and 310 A that are configured to engage a portion of the surface of respective vertebral bodies V 7 and V 8 , wherein the vertebral bodies V 7 and V 8 have been configured to engage with the bone-engaging surfaces 310 and 310 A, respectively.

After the prosthesis 400 is implanted and surfaces 310 and 310 A are engaged with the vertebral body V 7 and V 8 , at least at a location of area 324 of the junction 11 between the vertical surface 312 and the endplate surface 326 of the vertebral body V 7 (junction 11 not shown in FIG. 5 , but is represented as junction 11 in FIG. 1 ), an outer surface 324 S at area 324 of prosthesis 400 has a shape that is substantially similar to an anatomical shape of the vertebral body V 7 . An anatomical shape of junction 11 is shown in FIG. 1 . Note that prosthesis 400 comprises a portion 322 that is situated at the location of junction 11 , and the area where portion 322 engages the vertebral body V 7 is labeled by reference marker 224 . Similarly, as shown in FIG. 5 , at least at a location of area 324 A of the junction 11 A between the vertical surface 312 A and the endplate surface 310 A of the vertebral body V 8 (junction 11 A not shown in FIG. 5 , but is represented as junction 11 A in FIG. 1 ), an outer surface 324 AS at area 324 A of prosthesis 400 has a shape that is substantially similar to an anatomical shape of the vertebral body V 8 . An anatomical shape of junction 11 A is shown in FIG. 1 . Note that prosthesis 400 comprises a portion 322 A that is situated at the location of junction 11 A, and the area where portion 322 A engages the vertebral body V 8 is labeled by reference marker 324 A.

As shown in FIG. 5 , at the area 324 of junction 11 between the vertical surface 312 and the endplate surface 310 of the vertebral body V 7 , the bone-engaging surface 310 has a cross-sectional shape in a sagittal plane that comprises a convex shape 311 X, and the vertebral body V 7 has a concave shape 322 X at the same area 324 to engage with the surface 311 X. Note that the outer surface of area 324 of prosthesis 400 at portion 322 is labeled by reference marker 324 S. Also, similar to surface 310 , as shown in FIG. 5 , surface 310 A and vertebral body V 8 have similar configurations at the area 324 A of junction 11 A between the vertical surface 312 A and the endplate surface 310 A. That is, the bone-engaging surface 310 A has a cross-sectional shape in a sagittal plane that comprises a convex shape 311 AX, and the vertebral body V 8 has a concave shape 322 AX at the same area 224 A to engage with surface 311 AX. Note that the outer surface of area 324 A of prosthesis 400 at portion 322 A is labeled by reference marker 324 AS.

As shown in FIG. 5 , bone-engaging surface 310 prosthesis 400 may further comprise structures 328 to help affix prosthesis 400 to vertebral body V 7 . Structures 328 may be anchors, keels, spikes, pegs, prongs, or similar structures to help prosthesis 400 affix to vertebral body V 7 . Similarly, bone-engaging surface 310 A may further comprise structures 328 A to help affix prosthesis 400 to vertebral body V 8 . Structures 328 A may be anchors, keels, spikes, pegs, prongs, or similar structures to help component prosthesis 400 to vertebral body V 8 . Surface coatings such as Hydroxyapatite (HA), plasma spray or beading also may be used instead of or in addition to respective structures 328 and 328 A to help affix components to their respective vertebral bodies.

All adjustments and alternatives described above are intended to be included within the scope of the invention, as defined exclusively in the following claims. Those skilled in the art also should realize that such modifications and equivalent constructions or methods do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure. For example, prostheses 100 , 200 and 300 are shown as motion-preserving devices, but can be modified to be fusion devices. Similarly, although all of the prostheses above are described as being configured to affix to an endplate of a vertebral body and a vertical surface of a vertebral body that is an anterior surface of a vertebral body, all of the prostheses above may be configured to affix to a posterior surface of a vertebral body, a lateral surface of a vertebral body instead of or as well as an anterior surface of a vertebral body, or any plurality or combination or such surfaces.

Furthermore, as used herein, the terms components and modules may be interchanged. It is understood that all spatial references, such as “superior,” “inferior,” “anterior,” “posterior,” “outer,” “inner,” and “perimeter” are for illustrative purposes only and can be varied within the scope of the disclosure.